sql query compare two columns same table

Calculate the sum of order quantities $query_num"SELECT SUM(order_num) from hcf_order_db where order_id = XXX";$arr_qn = mysqli_query($dbc,$query_num);list($sum)=mysqli_fetch_row($arr_qn); Calculate the sum of the order Amount $query_amount"SELECT SUM(order_amount) from hcf_order_db where order_id = XXX";$arr_qm = mysqli_query($dbc,$query_amount);list($sum2)=mysqli_fetch_row($arr_qm); Then there is the PHP output: tdclass='font-songti'align='center'> echo$sum?> td>tdclass='f

How do you compare the size of two columns of numbers in an Excel table? 1, compared to the size of the two columns, such as the number of 2013 and 2012, if the 2013 month is larger than the number of 2012, the background is expressed 2, starting from C2, choose C2→c13. Note that the order is important

Explanation of IF and COUNTIF functionsIF (logical_test, [value_if_true], [value_if_false])Can't read English? Okay! Explanation:Logical_test: an expression that returns a boolean value,That is, TRUE or FALSE (TRUE or FALSE ),In layman's terms, this is right or wrong,TRUE (TRUE) if the expression is correct, for example: 1 If the expression is incorrect, it is FALSE, for example, 1> 2,In addition, the value 0 is false in EXCEL, because the basic language of EXECL is VB, and 0 is false in

I have two tables, all of which are mobile phone numbers. Table A contains Table B. The col001 columns of both tables are mobile phone numbers, Table B of column col002 is a number and table A is 0. To compare the two tables, as

In django, the Data Query condition is that the table columns corresponding to the foreign key in the table should be searched ?, Django table 1. Generally, the condition for finding data in a table is the existing data type in py

Use SQL to change the data type of a table's columns and add new columns and ConstraintsModify a column of a database table or add a column--Add a columnALTER table name ADD column name VARCHAR (+) NULL--Delete a columnALTER table

1. Simple Query　　A simple Transact-SQL query only includes the select list, from clause, and where clause. They indicate the queried columns, the queried tables or views, and the search conditions.　　For example, the following statement queries the nick name and email fields in the testtable

1. query the number of columns in the table Select count (column_name) from user_tab_columnswhere table_name = 'table name'; -- the table name is capitalized.Or: Select count (column_name) from user_tab_columns where table_name = upper ('

How does the column selection differ when Oracle queries are converted to SQL queries? The following describes how to select columns from Oracle query to SQL query. We hope that you can have a deeper understanding of Oracle query.

Access to Create a Table SQL statement Create Table to set AUTOINCREMENT for Automatically increasing columns, SQL statement createtable Access Table creation SQL statement Create

dropped. For example, if you create a table named employees, anyone who has security permissions to use the table in the database can use the table unless it has been deleted. If you create a local temporary table named #employees, only you can perform an operation on the table